Short answer: the Sony Bravia Theater Sub 9. Both are rated 3.7/5 for sound quality (#84 and #105 of 212 subwoofers), and the Sony Bravia Theater Sub 9 costs $598 against $624.44 for the REL Acoustics HT/1003 MKII, so with nothing between them on sound quality, price settles it.
What the REL Acoustics HT/1003 MKII does well: Dedicated home theater design with a front-firing 10-inch CarbonGlas driver and NextGen5 300W Class D amplifier. The tradeoff: Omits REL traditional high-level speaker wire input, connecting exclusively via line-level RCA/LFE.
Why pick the Sony Bravia Theater Sub 9: Independent CEA-2010 testing records 98.0 dB at 20 Hz and 112.8 dB through 40-80 Hz. Watch for: The 390.0H x 400.0W x 350.0D mm cabinet and 51.4 lbs (23.3 kg) mass still need deliberate placement.
Buy the Sony Bravia Theater Sub 9. Both are rated the same for sound quality, and it costs $26.44 less than the REL Acoustics HT/1003 MKII.
Worth knowing: the REL Acoustics HT/1003 MKII has not been measured yet. Its rating is estimated from related models, with a likely range of 3.5 to 3.9, so treat this verdict as provisional.
Looking for alternatives? See the complete Subwoofers rankings.
Specifications Side By Side
| REL Acoustics HT/1003 MKII | Sony Bravia Theater Sub 9 | |
|---|---|---|
| Price | $624.44 | $598.00 |
| Ranked | #105 of 212 in Medium Home Subwoofers (30-75 lbs) Estimated | #84 of 212 in Medium Home Subwoofers (30-75 lbs) |
| Country | United Kingdom | Vietnam |
| Warranty | 3 | 1 |
| Enclosure | sealed | sealed |
| Drivers | 10” (250mm) CarbonGlas cone, inverted carbon fiber dust cap | (2) 8” (200mm) drivers |
| Amplifier Power | 300W RMS (NextGen5 Class D) | - |
| Frequency Response | 24Hz at -6dB (manufacturer specified) | - |
| Dimensions | 14.3”H x 14.3”W x 15.5”D (362 x 362 x 393 mm) | 15.4”H x 15.7”W x 13.8”D (390.0 x 400.0 x 350.0 mm) |
| Weight | 34.2 lbs (15.5 kg) | 51.4 lbs (23.3 kg) |
| Output SPL at 16 Hz | - | 85.1 dB |
| Output SPL at 20 Hz | - | 98.0 dB |
| Output SPL at 25 Hz | - | 103.2 dB |
| Output SPL at 31.5 Hz | - | 109.1 dB |
| Output SPL at 40 Hz | - | 109.9 dB |
| Output SPL at 50 Hz | - | 114.0 dB |
| Output SPL at 63 Hz | - | 114.7 dB |
| Output SPL at 80 Hz | - | 112.8 dB |
| CEA-2010-A Average (40-80Hz) | - | 112.8 dB |
| Measurement Source | - | Brent Butterworth |
Related Speaker Comparisons
More worthwhile head-to-heads for Sony Bravia Theater Sub 9:
- Monoprice SW-15 vs Sony Bravia Theater Sub 9
- SVS SB-3000 vs Sony Bravia Theater Sub 9
- JBL Stage 220P vs Sony Bravia Theater Sub 9
- Polk Audio Signature Elite ES10 Subwoofer vs Sony Bravia Theater Sub 9
- Polk Audio Signature Elite ES10 Subwoofer vs REL Acoustics HT/1003 MKII
Prices on this page were last checked October 11, 2026 at 4:59 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
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The Two Speakers In Full
REL Acoustics HT/1003 MKII: $624.44 Estimated Amazon eBay
Same family: the REL Acoustics HT/1205 MKII (larger subwoofer, ranked higher, estimated 3.9/5) and the REL Acoustics HT/1510 Predator II (larger subwoofer, rated 4.1/5).
Pros: Dedicated home theater design with a front-firing 10-inch CarbonGlas driver and NextGen5 300W Class D amplifier. Delivers energetic, punchy bass response down to 24Hz (-6dB) in a compact, braced sealed cabinet.
Cons: Omits REL traditional high-level speaker wire input, connecting exclusively via line-level RCA/LFE. Sealed 10-inch cabinet runs into compression on sub-25Hz movie bursts compared to 12-inch and 15-inch models.
Full REL Acoustics HT/1003 MKII review and specifications →
| Amplifier Power | 300W RMS (NextGen5 Class D) |
|---|---|
| Country | United Kingdom |
| Dimensions | 14.3”H x 14.3”W x 15.5”D (362 x 362 x 393 mm) |
| Drivers | 10” (250mm) CarbonGlas cone, inverted carbon fiber dust cap |
| Enclosure | sealed |
| Frequency Response | 24Hz at -6dB (manufacturer specified) |
| Warranty | 3 |
| Weight | 34.2 lbs (15.5 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- No independent measurement review is linked for this model; it is ranked from hands-on listening and comparison against similarly priced speakers.
- Head-to-Head Comparisons
Sony Bravia Theater Sub 9: $598.00 Amazon eBay
Same family: the Sony Bravia Theater Sub 7 (smaller subwoofer, estimated 2.9/5) and the Sony Bravia Theater Sub 8 (smaller subwoofer, estimated 3.4/5).
Pros: Independent CEA-2010 testing records 98.0 dB at 20 Hz and 112.8 dB through 40-80 Hz. The sealed enclosure with (2) 8” drivers suits a mid-size room.
Cons: The 390.0H x 400.0W x 350.0D mm cabinet and 23.3 kg mass still need deliberate placement.
Full Sony Bravia Theater Sub 9 review and specifications →
| Released | Jun 2026 (4 months ago) |
|---|---|
| CEA-2010-A Average (40-80Hz) | 112.8 dB |
| Country | Vietnam |
| Dimensions | 15.4”H x 15.7”W x 13.8”D (390.0 x 400.0 x 350.0 mm) |
| Drivers | (2) 8” (200mm) drivers |
| Enclosure | sealed |
| Measurement Source | Brent Butterworth |
| Output SPL at 16 Hz | 85.1 dB |
| Output SPL at 20 Hz | 98.0 dB |
| Output SPL at 25 Hz | 103.2 dB |
| Output SPL at 31.5 Hz | 109.1 dB |
| Output SPL at 40 Hz | 109.9 dB |
| Output SPL at 50 Hz | 114.0 dB |
| Output SPL at 63 Hz | 114.7 dB |
| Output SPL at 80 Hz | 112.8 dB |
| Warranty | 1 |
| Weight | 51.4 lbs (23.3 kg) |
- Reviews, Comparisons and Sound Samples
- Independently measured by Brent Butterworth; the published figures above come from this ASR subwoofer measurement thread.
- Head-to-Head Comparisons
- Sony Bravia Theater Sub 9 vs JBL Stage 220P
- Sony Bravia Theater Sub 9 vs Polk Audio Signature Elite ES10 Subwoofer
- Sony Bravia Theater Sub 9 vs SVS SB-3000
- Sony Bravia Theater Sub 9 vs Monoprice SW-15
- Sony Bravia Theater Sub 9 vs Sony Bravia Theater Sub 7
- Sony Bravia Theater Sub 9 vs Sony Bravia Theater Sub 8